Consumer grade portable electronic devices such as multi-function smart phones, laptop personal computers, and dedicated navigation devices typically use lithium ion, Li-ion, or lithium polymer, LiPo, based rechargeable batteries as their primary power source. Such batteries have relatively high energy-to-weight ratios, making them well suited for portable applications. However, they are more “delicate” than other battery chemistries. In particular, to maintain their longevity or reliability, most Li-ion cells should be charged at a lower current when the cell temperature is down at 5° C. (41° F.) or colder. In addition, charging at below freezing is to be avoided because permanent damage to the internal structure of the cell could occur. For this reason, a typical portable electronic device has a temperature sensor and a charging circuit that automatically prevents its battery from being charged when it is too cold. Thus, for example, if a user has left the device in his car overnight while the ambient temperature has dropped to below freezing, it may take a long time before the battery is fully charged (depending on how quickly the device can be brought up to a minimum charging temperature).